Quality of Service (QoS) is an important technology in the Next Generation Network (NGN), and the QoS control architecture of an access network has been proposed currently in the Telecommunication and Internet converged Services and Protocols for Advanced Networking (TISPAN). FIG. 1 illustrates a schematic diagram of the QoS control architecture of an access network, which can be divided into an access network; a core network; an Application Function (AF) by network affiliations, wherein the access network includes an Access Node (AN); an Access-Resource Admission Control Function (A-RACF); and an Internet Protocol-Edge Function (IP-EDGE). The core network includes a Session Policy Decision Function (SPDF) and a Core-Edge Gateway Function (C-BGF), which can be divided into a Resource Admission Control Subsystem (RACS), a transport layer, a Network Attachment Subsystem (NASS), and an AF, by network functions, where the RACS includes an A-RACF and a SPDF, and the transport layer includes an AN, an IP-EDGE, and a BGF.
The SPDF is a service-based policy decision module to provide the AF with a Gq′ interface and a bearer service. A User Equipment (UE), when requesting for a service, establishes a session with the AF through the transport layer, and the AF extracts QoS request parameters from the service request in the session and initiates to the SPDF a QoS resource request, including a category of the service, a bandwidth, five-tuple information of a flow, a user identifier, a flow operation instruction, etc.; that is, the AF requests the SPDF to build a QoS channel at the transport layer for the specific service. The SPDF stores a policy rule, makes a service-based policy decision, locates the access network where the UE is located and the A-RACF therein, and transports the QoS resource request to the located A-RACF via an Rq interface, the A-RACF being responsible for QoS control of the service. The A-RACF performs QoS control of the service by a process as follows: the A-RACF receives a QoS resource request forwarded by the SPDF via the Rq interface, obtains provided subscription data and location information of the UE from the NASS via an e4 interface, determines whether to provide the UE with the QoS in accordance with the obtained information, and sends a response of admitting the QoS request or not to the SPDF, after bandwidth reservation of the access network and instructing the IP-EDGE and the AN at the transport layer of the access network to execute the QoS.
For an executable QoS resource request, the A-RACF transports a QoS execution operation command to the IP-EDGE and the AN via a RE interface and a Ra interface, in accordance with the flow operation instruction in the QoS resource request to instruct the IP-EDGE and the AN to reserve resources required by the QoS, and the SPDF instructs the C-BGF to reserve resources required by the QoS of the service via an la interface.
UE end-to-end QoS management, control and execution can be supported in the schematic diagram illustrated in FIG. 1. Furthermore, function divisions and interfaces for reference are provided for networks affiliated with different Network Service Providers (NSP), e.g. network operators, service providers, etc., and capabilities of authentication and charging between the networks affiliated with the different NSPs are provided.
Currently, an access network and a core network in the NGN are operated by different NSPs; that is, the access network and the core network are provided with different management domains, and this requires a capability of the access network to provide the UE with different core networks. Thus, there may be two or more IP-EDGEs in an access network, which are connected, respectively, with C-BGFs of two or more core networks, and if there is only one SPDF in each core network, then a plurality of SPDFs may be in signaling connection with the A-RACF in the access network, as illustrated in FIG. 2.
In FIG. 2, an access network can be connected to a core network affiliated with a NSP1 and a core network affiliated with a NSP2, and there is a plurality of link connections at the transport layer between the access network and the two core networks. The situation illustrated in FIG. 2 can be roughly divided into two primary scenarios: 1. there is a plurality of different IP-EDGEs in the access network, which are in one-to-one correspondence to C-BGFs of the core networks in different management domains; and 2. an IP-EDGE in the access network corresponds to the C-BGFs of the core networks in the different management domains. While reserving QoS resources for a service, the A-RACF of the access network has to locate a path over which the service traverses a boundary between the access network and the core network; otherwise, it is impossible to execute any QoS operation of the service. Accordingly, the Rq interface between the SPDF and the A-RACF is required to provide a capability to select a link of the different networks between the management domains, but the existing Rq interface has not yet supported the capability.
In the first scenario illustrated in FIG. 2, the A-RACF of the access network can obtain the identifier of the SPDF through the signaling connection and searches for a corresponding IP-EDGE, in accordance with its preset correspondence table of SPDF identifiers and IP-EDGEs, thereby establishing a link connection between the BGF and the IP-EDGE. In the second scenario illustrated in FIG. 2, a plurality of IP-EDGEs may be found from a search in the preset correspondence table of SPDF identifiers and IP-EDGEs, and, consequently, it is still impossible to select and further establish a link connection between the BGF and the IP-EDGE.
The above descriptions have been given merely taking establishment of a link between the access network and the core network in the NGN as an example, and actually there is no method for selecting an edge connection link across different management domain networks in the case of a plurality of links between the different management domain networks.